1. Field of the Invention
The present invention relates generally to the art of poppet seats and more particularly to poppet seats useful in air regulating devices. In its most preferred embodiment, the present invention relates to an improved poppet seat in which synthetic or natural rubber seat material is molded around and through an annular carrier. The invention also relates to a method for making a poppet seat of this type.
2. Description of the Prior Art
In the field of air regulating devices, such as those used in underwater diving equipment (more commonly known as scuba equipment) breathable air is provided to the diver from a pressurized air source, e.g. a compressed air cylinder, a surface supply hose, etc.
In most equipment a primary regulator is employed to reduce the air pressure available to the diver from the pressurized source, such as a pressurized air tank, and a demand regulator functions to supply air in accordance with the diver's breathing pattern. In current demand regulators, poppet seats have been commonly manufactured by providing a carrier base made out of plastic or metal material and having a groove about its center. Pliable seat material has been added to the groove and has been held in place by friction and/or by adhesive bonding. In one prior art device, such seats were exposed to pressures in the range of 120-150 pounds/in.sup.2 and made spring loaded contact with a coned orifice member to provide a complete seal of the pressure. Such poppet seats are subjected to widely varying environmental conditions and cyclic use since each time a breath is taken, a spring is relieved thereby allowing movement of the coned orifice member toward and away from the seal and permitting the bypass of breathable air to the scuba diver.
Such poppets have proved to be highly effective over extended periods of time, but several design aspects of the current system make it possible for small leakage to occur. For example, the coned orifice can become damaged or the seating surface itself may be contaminated or deformed. These occurrences are especially likely in situations where the regulator is not maintained properly, e.g. if it is not reused as recommended by most manufacturers. Leakage could also occur if the seat material becomes delaminated from the substrate carrier base, as could happen for example if the adhesive or frictional forces became weakened. If any of these occurrences would take place while the diver was below water, normal emergency procedures, such as the use of a back-up regulator, would be employed to allow a divers safe return to the surface. Repair of this regulator would then be required.
While the first two problems mentioned above may be readily cured by proper maintenance, the later problem is less easy to observe, as it can occur over time. An improvement in design would be desirable to make sure the air supply is not bypassed due to inappropriate separation of the seat material from the carrier component.